Darkstalkers series (I remember playing this in a crappy movie theater - it's practically the only good thing I do remember about that theater. I've since become an extremely devoted fan.)
Street Fighter III series (I remember playing New Generation when I went on a vacation with the family, and immediately fell in love with it. Played the sequels at random other places as well.)
X-Men (Can't even remember where I played this first, although I did just play it again very recently at M.C.Chris' tour.)
Simpsons (I remember playing this one on a school field trip to Chuck E Cheese. Again, about the only worthwhile thing I remember about that field trip.)
Captain America & The Avengers (Same theater that I played SF3:TS at, only much much earlier, obviously. THE... AVENGERS!)
Fatal Fury III (Pizza Hut used to have tons of Neo-Geo cabs, and this one got tons of play from me and my friends. Used to rock the house with Mary and Sokaku.)
Metal Slug 2 (Pizza Hut, again. I played this one to the point where I eventually one-credit completed it - to this day, my greatest gaming accomplishment and the only arcade game I can recall doing that with aside from fighting games.)